Using CRISPR/Cas9 engineering to generate a mouse with a conditional knockout allele for the promyelocytic leukemia...

The promyelocytic leukemia zinc finger (PLZF) transcription factor mediates a wide-range of biological processes. Accordingly, perturbation of PLZF function results in a myriad of physiologic defects, the most conspicuous of which is abnormal skeletal patterning. Although whole body knockout of Plzf in the mouse (Plzf ^KO ) has significantly expanded our understanding of Plzf function in vivo, a conditional knockout mouse model that enables tissue or cell-type specific ablation of Plzf has not been developed. Therefore, we used CRISPR/Cas 9 gene editing to generate a mouse model in which exon 2 of the murine Plzf gene is specifically flanked (or floxed) by LoxP sites (Plzf ^f/f ). Crossing our Plzf ^f/f mouse with a global cre-driver mouse to generate the Plzf ^d/d bigenic mouse, we demonstrate that exon 2 of the Plzf gene is ablated in the Plzf ^d/d bigenic. Similar to the previously reported Plzf ^KO mouse, the Plzf ^d/d mouse exhibits a severe defect in skeletal patterning of the hindlimb, indicating that the Plzf ^f/f mouse functions as designed. Therefore, studies in this short technical report demonstrate that the Plzf ^f/f mouse will be useful to investigators who wish to explore the role of the Plzf transcription factor in a specific tissue or cell-type.